Simulation in Opnet

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A comparative study of wireless communication protocols for

monitoring vital signs in athletes in a soccer field

G.KIOKES1,P.GKONIS

2,E.ZOUNTOURIDOU

2

1Department of Electronics, Electric Power and Telecommunications,2School of Electrical and Computer Engineering,

1Hellenic Air-Force Academy,

2National Technical University of Athens,1Air Base Dekeleia,

29 Iroon Politechniou str. ,Zografou, Athens

GREECE

[email protected],[email protected], [email protected]

Abstract: - This paper provides a comprehensive investigation of two wireless protocols performance over short

range communications for monitoring vital signs in athletes, mainly during training. Live physiologicalmonitoring of athletes during sports can help to optimize their performance at a specific time in order tomaximize athlete efficiency and preventing undesirable events like injuries. ZigBee (over IEEE 802.15.4) isbecoming a popular way to create wireless personal area network due to its low power consumption andscalability while Wi-Fi (over IEEE 802.11g) provides the solution for portability with connection of mobility aswell. This article presents the evaluation results of system performance using OPNET simulation for the twodifferent wireless standards. The evaluation is concentrated on providing results regarding network values such

as end-to-end delay, traffic, average throughput captured from global and objects statistics.

Key-Words: -Wireless sensor networks, Performance evaluation, OPNET, Simulation, Throughput

1 IntroductionThe evolution on sensors technology over the lastdecades has opened completely new fields for the

modern technological applications. Nowadays,wireless sensors networks (WSNs) [1] constitute apromising field of research in the area of WirelessCommunications, given the extensive breadth ofapplications that they can support. They represent a

new order of operating calculating systems thatextends the interaction between humans and the

natural environment. While up to today the wired

sensors networks were globally used, the growth ofmicroelectronic systems technology in the wirelesscommunications sector, made feasible the use

wireless sensors. The wireless technology providesmore flexibility, easiness of use and fast growth ofsensors networks; although in certain critical

applications there are data transfer reliability issues.More analytically, the WSNs are constituted by oneor more sink or base stations and by tens orthousands sensor nodes, which are scattered in a

space. These nodes collect information from theenvironment and depending on the application,

either process the information and send it to acentral node, or they send it without processing.

These nodes, usually sensor the temperature, thelight, the vibration, the sound, e.t.c.. This

information travels into the network, having asfinal destination the nodes sink. Depending on theapplication, sinks sent queries to the nodes, in orderto gather useful information.The most important advantage of this type ofnetwork is that, the beforehand knowledge of thetopology is not required. This ability allows the

rapid growth of networks in remotely and wildregions. The nodes have low cost and lowconsumption, as they have the ability ofcommunicating in small distances, executing limited

local data process and sensor signals of varioustypes, in their application region. A sensor network

is characterized from its lifetime, its expandability,its coverage, the production cost, the fault detection

and correction, its synchronization, the responsetime, as well as the safety it provides. The storage

energy capacity of the devices is the restrictivefactor of life duration. It should be noted that thecritical characteristic in a lot of applications, is not

the average lifetime of one node, but the minimum

estimated lifetime.Training is a repeating (rollover) process consistingof four steps: assessment, planning, implementation,

WSEAS TRANSACTIONS on COMMUNICATIONS G. Kiokes, P. Gkonis, E. Zountouridou

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and monitoring [2]. Overtraining is a non desirableprocess of excessive exercise training in high-performance athletes that may lead to overtraining

syndrome. According author [3], overtrainingsyndrome is a neuroendocrine disorder

characterized by poor performance in competition,inability to maintain training loads, persistentfatigue, reduced catecholamine excretion, frequentillness, disturbed sleep and alterations in mood state.

In order to detect overtraining, the training load ofeach athlete needs to be monitored and

individualized. Monitoring training load requiresquantification of the intensity and duration of thephysiological stress imposed on the athlete.Consequently, training volume and intensity are thebasic training variables that characterize training

load [4],[5].

Athlete monitoring is key to achieving both shortterm and long term competitive success. The moreconsistent the monitoring, the more meaningful theinformation will be. The increased athleticcompetiveness and at the same time the technology

revolution, led to discover ways of monitoring theathletes training and performance. Monitoring eachathlete data, such as heart rate, nutrition, providesuseful information, enabling the personalization of

the training, avoiding overtraining, which eventuallylead performance maximization. In recent years,several wireless access technologies are broadening

and changing our habits. Each wireless solutionoffers a specific mix of transmission band, costs,and coverage according to the needs that originatedit.

A comparative study of the two technologies isgiven in [6]. The authors presented a broad

overview of the four most popular wirelessstandards, Bluetooth, UWB, ZigBee, and Wi-Fi witha quantitative valuation in terms of the transmissiontime, data coding efficiency, protocol complexity,and power consumption. The performance analysis

of the 802.15.4 standard has been extensively

studied in the literature such as [7], [8], [9]. Forinstance, in [7] authors investigate the performanceof the aforementioned network through simulationsin the OPNET Modeler environment and came tothe conclusion that the ZigBee protocol is well

suited for monitoring athletes subscribers andsimilar applications.

In this paper, firstly an overview of the mentionedwireless protocols is presented. Following a

performance evaluation comparison of the twostandards in an soccer athletic field area isconducted using OPNET simulator, in order to

investigate the more appropriate protocol formonitoring athletes vital signs by training. A

specific scenario is analyzed and simulated and thennetwork values such as end-to-end delay, traffic andthroughput are exported. The rest of this paper is

organized as follows. Tthe architecture of theprotocols specified for wireless sensor networks is

described in Sec. 2. Following that, Sec. 3 presentsthe simulation results achieved by using OPNETSimulator for Physical and MAC layer performanceestimation. Finally, conclusions are given, offering

quantitative evaluation of the proposed approach inSec. 4.

2 Wireless Technologies verview

2.1 Zigbee

IEEE 802.15.4 standard [10], determines thespecifications of the Physical layer and the MediumAccess Control (MAC) sub-layer of wirelesspersonal area networks (WPANs) using devices theyconsume low power. ZigBee systems are beingdesigned to provide wireless short-range

communications (up to 100m), depending on poweroutput and environmental characteristics.

WSN have particularly different requirements thanstandard local networks of ultra-high datatransmission speed. It is reminded that devices likesensors are able to record and transmit information

to environments inaccessible to human factors forparticularly long periods. This implies that thedesign of each protocol related to them must take

account of the following features:a) the need for low power and energy consumption,

b) the need for self-configuration of the wirelessnetwork and adaptation thereof to the environment

data, andc) the signal shielding mechanism againstinterference, at physical level.

On another aspect, the high transmission speeds

required in WLAN is of no particular concern, asthe information usually transmitted relate to the

recording of certain environment data (that is a fewbytes of information) and not large volume files, asin the case of WLAN.

ZigBee specification focuses only on upperlayers (Fig. 1): starting from the network layer to the

final application layer, including the applicationobjects themselves. The ZigBee application layer

consists of the Application Support sub-layer (APS),the ZigBee Device Object (ZDO) and themanufacturer-defined application objects. The

responsibilities of the APS sub-layer includemaintaining tables for binding, which is the ability


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to match two devices together based on theirservices and their needs, and forwarding messagesbetween bound devices. Another responsibility of

the APS sub-layer is discovery, which is the abilityto determine which other devices are operating in

the personal operating space of a device [11].Wireless connections under 802.15.4 standard

can operate in three ISM (Industrial ScientificMedical) frequency bands with the following data

rates:1) 250kbps in the 2.4 GHz band (O-QPSK

encoding),2) 40kbps in the 915 MHz band (BPSK encoding)and3) 20 kbps in the 868 MHz band (BPSK encoding)

Fig. 1 ZigBee Communication Stack

2.2 The WI-FI standardWireless Local Area Networks (WLANs) are one ofthe internet-related technologies that during the last

decade marked the greatest expansion at globallevel. The replacement of analog lines with digital

ones, the expansion of optics communications (fiberoptics), and the increased information transmission

rates occurred in parallel to the replacement ofcertain wired functions by wireless ones. Currently,

every household, or work area with internet accesssupports a wireless network through the routerantenna and the wireless network card of a laptop.Therefore, it is obvious that any design at least in

an urban environment - of a network other thanWLAN, such as those of 802.15.4 which operate in

the same frequencies and at a lower transmissionstrength, must take into account the interferencecaused by wireless local area networks.

IEEE 802.11 protocol defines two types ofequipment (Fig 2), a wireless station, which is

usually a PC equipped with a wireless networkinterface card and an access point acting as a bridgebetween the wireless and wired areas of the

network. The access point usually consists of anantenna, a wired network interface and a software

that responds to protocol 802.11d, which transfersdata from the wireless to the wired network. Accesspoint operates as a base-station for the wirelessnetwork, allowing multiple terminal devices

connection to the wired network. IEEE 802.11standard defines two operating modes: (a)

infrastructure mode and (b) ad hoc mode [12]

Fig. 2 Wi-Fi network topology

Wi-Fi standard defines the following networkingtopologies:

IBSS (Independent Basic Service Set) or ad hoc

topologyThis is the most simple wireless network topology(Fig. 3). The stations are peers and communicate

directly between them, peer to peer, without acentral station. This networking mode is usedprimarily by small networks. A necessaryprecondition for the communication between two

stations is that each one is within the range of theother.

Fig. 3 IBSS topology

Infrastructure

BSS topology is a more complex networkingtopology in which the wireless network has clusterform. In each cluster there is a number of wireless


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stations (clients), which communicate between themthrough a central distributor BS (Base Station) or,more commonly, AP (Access Point).

There is determination of two service types,depending on the number of Aps, and therefore the

number of clusters [13]:a) Infrastructure Basic Service Set.b) ESS, Extended Service Set

A wireless network can also consist of more than

one clusters, which can be bridged over aDistribution System. The distribution system is the

network connecting APs between them and with theother networks. The entire interconnected network,including the distribution system and the APsconstitutes the ESS topology. That is, it is a set ofclusters, each one of which consists of an access

point AP, with all APs being connected to a network

structure. This achieves larger wireless coveragerange. In this case, each wireless station cancommute from on cluster to the other without thestation itself, or the network experiencing anychange. This ability of the network is called

roaming.IEEE 802.11g protocol operates on the same

bandwidth with 802.11b, namely 22MHz, whichallows it to achieve higher transmission speeds.

Moreover, depending on the environmental noise,the protocol is able to select among new operationspeeds which are 6,9,12,18,24,46,48,54Mbps. In

addition, it is compatible with 802.11b as it can alsosupport 1, 2, 5.5 and 11Mbps speeds using DSSSand CCK encoding. The need to increasetransmission speeds while maintaining bandwidth at

22MHz, in conjunction with the resistance of thesystem to intersymbol interference, were the key

parameters for the use of a new configuration,OFDM (Orthogonal Frequency DivisionMultiplexing). New speeds (6,9,12...54) are theresult of OFDM configuration. OFDM is the soleconfiguration able to achieve high transmission rates

while resisting interference. The following table

depicts the frequency bands and the theoretical andactual speeds of the various 802.11 standards [14]

Table 1 The frequency bands of 802.11 standard

Standard

Frequency Band

Typical

Transmission Rate

Theoretical

Transmission Rate

Range

Indoors

802.11a 5GHz 23Mbps 54Mbps 35m

802.11b 2.4GHz 4.3Mbps 11Mbps 38m

802.11g 2.4GHz 19Mbps 54Mbps 38m

3 Simulation Results

3.1 Simulation model descriptionOPNET Modeler [15] constitutes a specialized tool

in the area of communications, having graphicenvironment for modelling and simulation, ofvarious types of networks. The platform allows the

design and thorough study of telecommunicationnetworks offering great flexibility depending on thelayer of the network concerned. Moreover

simulating separate models for each network, it ispossible to take measurements of global and objectparameters, such as packet delay, packet loss,throughput, e.t.c. and through them can export

general conclusions of the systems performance.The main objective was the development and

study of the two communication networks betweenathletes and coordinator (coach). The area selected

for the simulation was a typical soccer field. Thelength of a full-size soccer pitch must be between

100 yards (90 metres) and 130 yards (120 metres)and the width between 50 yards (45 metres) and 100yards (90 metres) with 11 players. Each of the 11players was able to move in a specific territoryclockwise in a parallelogram trajectory round the

area depending on its playing position. For example,a Goalkeeper player, can move along the sidelines

of the playing area near the goalposts (Fig. 4 andFig. 5). The subscribers are moving with differentspeeds (10 to 15 Km/h). The scenario primaryobjectives were the recording of the communication

link between the nodes and the coach, the collectionof the identification and status data transmitted overa short period of time for each network topologywhereas depending on the results, conclusionswould arise regarding each protocols performance.

Fig. 4. Geographic positioning in simulation environmentfor WLAN IEEE 802.11g protocol


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Fig. 5 Geographic positioning in simulation

environment for ZigBEE protocol.

At the beginning, mobile stations of the network

were requested to send a large amount ofinformation related to their status. For this reason, inthe simulation model, the size of packets transferredvia Database Access application was set to MediumLoad. The duration of the simulation was selected tobe 10 minute due to the amount of data required tobe processed. Data rate was set to 250 kbits/secondin the 2.4 GHz for ZigBee and 54 Mbits/second in

the same frequency band for 802.11g.

3.2. ResultsOne can collect values from individual nodes in thenetwork (node statistics) or from the entire network

(global statistics). Global statistics can be used togather information about the network as a whole.

Node statistics provide information about individualnode such as coordinator, router or end device. The

eleven nodes in the athletic field topology wereidentical. The Global Statistics of the network,whose graphs will be examined, are listed and

analyzed in the following:

End to End delay (sec): is the time that

lapsed between creation and reception of anapplication packet.

Throughput (bits/sec): Represents the totalnumber of bits (in bits/sec) forwarded from wirelessLAN to higher layers in all WLAN nodes of thenetwork.

The Node Statistics for the Coordinator and onenode (player 5) of the network are analyzed below:

Throughput (bits/sec): represents the totaldata traffic in bits/sec successfully received and

forwarded to the higher layer by the WLAN.

Data traffic received (bits/sec): represents

the average number of bitsper second for trafficsuccessfully received by the MAC from the physical

layer. This includes retransmissions.

Data traffic sent (bits/sec):represents the

traffic transmitted by the MAC in bits/sec. While

computing the size of the transmitted packets for

this statistic, the physical layer and MAC headers of

the packet are also included.

The results and graphs are presented in thefollowing Figs 6-10. Fig. 6 demonstrate the end to

end delay of the network for the 802.11g (bluecurve) and ZigBee (red curve) technologies

respectively. As a result, the delay is higher inZigBee than in 802.11g. The main reason for this isthe different data rate according the usedtechnology. The next graph (Fig. 7) represents

network throughput (bps). It can be seen thatthroughput is heavily influenced by the traffic load

since none of the networks achieves theoreticaltransmission values and 802.11g performs better.

Similarly results can be obtain for Fig. 8. It can beenobserved that WIFI throughput is higher andcoordinator does not accept packets until the

pending data are not completely transmittedavoiding collisions situations. Fig. 9,10 represents

traffic received and sent (bits/sec) values forcoordinator and node 5 player. In both cases, it is

observed that WLAN technology continues toperform better. Fig. 11 and 12 also shows that all

nodes have more or less equivalent traffics.Takingeverything into account 802.11g provides fastnetworking connections and outperform the otherstandard.

4. CONCLUSIONSThe objective of this paper is to examine the

performance of the IEEE 802.11g and IEEE802.15.4 standards for wireless sensor networksapplications. At the beginning an overview of thetwo wireless technologies adapted in monitoring

vital signs of athletes, mainly during training ispresented. Furthermore through simulations in

OPNET Modeler environment global and nodestatistics in soccer field area with eleven nodes isexamined. The trajectory on each mobile node isconfigured on specific destination round the field.According to simulation results the 802.11g

protocol tends to outperform IEEE 802.15.4protocol mainly due to its high transmission rate.

More specific it gives less network end to end delayand higher average throughput.

In the future authors intend to perform furtherexperiments in order to examine power consumption

and energy efficiency of the two technologies.


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ZigBee's lower data rates, can support much lowerpower consumption rates. Extending this workauthors will develop the whole physical layer

transmitter and receiver for the two protocols usingNallatech XtremeDSP Development Kit with Xilinx

FPGA for real time implementations and study thetheoretical model variation.

Fig. 6. Global statistics - end to end delay (sec) comparison for both protocols

Fig. 7. Global statisticsThroughput (bits/sec) comparison for both protocols

Object (global) - IEEE 802.15.4(bits/sec) Object (global) - IEEE 802.11g (bits/sec)

Object (global) - IEEE 802.11g(bits/sec) Object (global) - IEEE 802.15.4 (bits/sec)


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Fig. 8. Coordinator statisticsThroughput (bits/sec) comparison for both protocols

Fig. 9. Coordinator statistics -Traffic received, Traffic sent (bits/sec) comparison for both protocols

Object (Coordinator) - IEEE 802.11gTraffic Rcvd (bits/sec) Object (Coordinator) - IEEE 802.15.4 Traffic Rcvd (bits/sec)

Object (Coordinator) - IEEE 802.11g- Traffic Sent (bits/sec) Object (Coordinator) - IEEE 802.15.4 Traffic Sent (bits/sec)

Object (Coordinator) - IEEE 802.15.4(bits/sec) Object (Coordinator) - IEEE 802.11g (bits/sec)


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Fig. 10. Player 5Router device statistics - Traffic received, Traffic sent (bits/sec) comparison for both

protocols

References:

[1] Akyildiz F. and Kasimoglu I.H., Ad HocNetworks 2(4):351-367, 2004

[2] Cambetta V. (2007), Monitoring training iscritical for success.http:// www.Humankinetics .com /excerpts/excerpts/monitoring-training-is-critical-for-

success[3] MacKinnon L. Overtraining effects on

immunity and performance in athletes,Immunology and Cell Biology 78:502509,2000

[4] Monoem H., Behm D., Tebben M. and K.Chamari,Monitoring Training Load, Recovery,

Overtraining and Upper respiratory Infectionin Taekwondo. Performance Optimization inTaekwondo: From Laboratory to Field. OMICSGroup International, 2014

[5] Foster C., Hector LL., Welsh R., Schrager M.,

Green MA., Effects of specific versus cross-training on running performance., Eur J ApplPhysiol Occup Physiol. 70:367-372,1995

[6] Jin-Shyan Lee, Yu-Wei Su, and Chung-ChouShen., A Comparative Study of Wireless

Protocols: Bluetooth, UWB, ZigBee, and Wi-Fi., IEEE Ind. Electr. Society Conf., Taipei,Taiwan, 2007

[7] Kiokes G., Vossou C., Chatzistamatis P., et.all.Performance Evaluation of a CommunicationProtocol for Vital Signs Sensors Used for theMonitoring of Athletes, Int. J. Of Distrib.

Sensor Networks. 2014

[8] Mahajan R., Nair S , Performance Evaluation

of Zigbee Protocol Using Opnet Modeler forMine Safety, Int. J. of Comp. Science and

Network, 2013[9] Mihajlov B. and Bogdanoski M., Overview and

Analysis of the Performances of ZigBee basedWireless Sensor Networks, Int. J. of Comp.

Applications, 2011[10]Feng Xia, Ruonan Hao, Yang Cao, and Lei

Xue, A Survey of Adaptive and Real-TimeProtocols Based on IEEE 802.15.4, Int.J.ofDistrib. Sensor Networks, 2011

[11]OPEN-Meter project ,Description of state- of-the-art wireless access technology, OPEN-

Meter WP2 D2.1 part3 v1.0. 2009[12]Ian Poolehttp://www.radioelectronics.com/info

/wireless/wi-fi/ieee-802-11-standards-tutorial.php Accessed 03 Jan 2015.

[13] Shooshtary S. ,Development of a MATLAB

Simulation Environment for Vehicle-to-Vehicleand Infrastructure Communication Based onIEEE 802.11pMaster Thesis, University ofGavle, Vienna, 2008

[14]IEEE-SA.IEEE 802.11: Wireless LAN Medium

Access Control (MAC) and Physical Layer(PHY) Specifications,2012 revision.

[15] Riverbed (2012), Riverbed application andnetwork performance management solutions.http://www.riverbed.com/products-solutions/products/opnet.html?redirect=opnet

Object (Player 5) - IEEE 802.15.4Traffic Rcvd (bits/sec) Object (Player 5) - IEEE 802.11g Traffic Rcvd (bits/sec)

Object (Player 5) - IEEE 802.15.4- Traffic Sent (bits/sec) Object (Player 5) - IEEE 802.11g Traffic Sent (bits/sec)


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